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Automatic trim commissioning
The unit is able to automate the above procedures, automatically calculating and entering flow val-
ues, oxygen trim setpoints, and boiler transport delay. The automatic commissioning procedure will
only work if the following conditions are met:
•
Option parameter 30.9 (automatic trim commissioning) is set to 1
•
An oxygen probe is fitted and fully operational
•
The unit is in adjust ratio with the burner firing a single fuel only
•
A hydrocarbon ratio has been entered for the current fuel (see option parameters 36.4 – 36.6).
The auto commissioning procedure will usually take between 10 and 30 minutes (depending on num-
ber of setpoints), and is performed by the unit as follows:
1.
Beginning with high fire, the unit moves the drives to each point in the firing range. The display
will show ‘Flow calc An’.
2.
When the measured oxygen reading settles, the unit stores the measured oxygen reading as the
new oxygen setpoint.
3.
The unit moves the air drives up to the point above the current setpoint, leaving the fuel drive in
the same position. The display will show ‘Flow calc An + 1’.When the new oxygen reading set-
tles, the unit calculates and stores the new flow value. If the oxygen reading exceeds 15.0% dur-
ing this stage, the unit shuts the burner down with F77.
4.
When the unit has completed the low fire point, the measured boiler transport delay (at low fire)
is stored in option parameter 30.7. Option parameter 30.5 (oxygen trim enable) is set to zero.
WARNING: Before enabling trim, use Adjust Ratio Mode to manually check the calculated
flow values, oxygen setpoints and transport delay. The low fire percentage flow value should
conform approximately to the turn-down ratio of the burner.
To perform automatic trim commissioning, follow the procedure below:
1.
Calibrate the oxygen probe.
2.
Enter adjust ratio mode.
3.
Enable automatic trim commissioning by setting option parameter 30.9 to 1.
4.
Wait for procedure to finish.
5.
Re-calibrate the oxygen probe.
6.
Check that the O
2
, flow and transport delay values are sensible.
